Motor-pump unit



Jan. 22, 1946: A S 2,393,406 MOTOR-PUMP UNIT Filed July so, 1942 Him , z 17 I v44 5 5 21 24 as 1m 3b Jokn ,Bfiaraowa I the character I Patented Jan. 22,1946

assists g j Moron-rosin v 'John 1;. Parsons Toledo, Ohio Application July so, 1942, Serial N 452,865

. 2 Claims. (CL 103-42) This inventionrelates to fluid. pumps but more particularly to liquid pumps adapted for use in 'automatic systems, such as for operating. windows of automobiles, and an object is to pro duce a simple and eillcient assembly by which the motor,. pump and reservoir form a compact. unit adapted to be readily and conveniently l mounted in position ot use, thereby materially to reduce assembly and installation expense, as well as space required for such apparatus.

Another object is to produce a pump unit of cribed having the novel features oi construction arrangement and operation here inaiter described. v v i For purposes of illustration but not oi limitation, an embodiment of the invention is shown tion of the pump, the liquid drawn from the reservoir will not'flnd its way along the shaft I! to o the electric motor. imposed by the liquid on the packing unit 24, a J small passage 24' leads from the under side of mature shaft in This vrotor a series 01 teeth whichprogressively mesh with teeth formed on a second rotor 22, Pumps of this character are I old in the" art so that more detail description is not considered-necessary. Sufiice it to say that the pump illustrated is available on the 'open j.;

market under the trade name oi Gerotor.

' On the upper side of the sleeve I8 is a socket 23 to receive a packing unit 2| which provideson the accompanying drawing in which Figure 1 is a side elevation ot a unit including a motor, pump and reservoir mounted in position of use;

Figure 2 is an enlarged fragmentary vertical sectional elevation showing particularly the vpump, mounting therefor, valve, associated ports and passages, and reseriroir;

Figure 3 is a transverse sectional view sub-. stantially on the line 3-4 of Figure 2: and

Figure 4 is an enlarged fragmentary sectional view showing the pump mounting and spring tensioned outlet valve, the latter being in partially depressed position.

The illustrated embodiment of the invention comprises an upright assembly including an elec-- tric motor arranged within a housing III, a block or casting ll containing a pump and valve unit, and a reservoir II. The reservoir l2, which may be of sheet metal, is cup-shaped and is formed with a transverse groove l3 at the bottom end to receive a bail H which is hingediy connected to the block H at its inner end. By swinging the bail H upwardly away from the reservoir l2, the latter can be removed. It will be observed that the block H is formed with an annular packin containing groove It to receive the open end of the reservoir. thereby affording a satisfactory seal between these parts.

Mounted on the outer side of the motor housing it is a solenoid actuated switch 16 of a y suitable construction controlling the operation of the electric motor within the housing III. The

motor has an armature shaft H which extends 1;; through a sleeved portion ll of the block ll into t an annular cavity l9 which contains a rotary an oil seal for the shaft ll so that in the opera- In order to relieve pressure,

the unit 24 to the port 28, hereinafter described.

In this mannerexcessive wear of the packing against the armature shalt i1 is prevented,

At one side or the pump is a tube 25, the lower end of which termihates adjacent the closed or bottom end of the reservoir l2 in order at all I times to be immersed in the liquid contained in same. The upper end of the tube 25 fits within the member I I and communicates with a port 28 which opens into a transverse or inlet passage 21. The passage 21 communicates with an arcuate port 28 which opens to the inlet side of the pump 20. Thus liquid is drawn from the reservoir it, through the tube 26 and through the port 28, and then is forced through the passage 21 and port 28 to the inlet sideoi the pump 20. The outer end oi the passage 21 has screw threads 28 to receive either a plug for closing that end or to receive one endof a tube which may lead, for example, from a cylinder-piston arrangement in which liquid is forced into one or the other end of the cylinder for driving the piston in one direction or the other and to enable the liquid at one side of the piston to be returned to thereservoir. In any case, a tube may be connected to the screw threaded opening 29 for returning the liquid to the reservoir 12 and it will be observed that this connection is so arranged that the returned liquid will augment the suppl drawn through the tube as.

Liquid from the discharge end or the pump 20 passes through an arcuate port 30 formed in the member I i. Communicating with the port 30 is a lateral passage 3| substantiall in alignment with the passage 21. In the passage 3| is a cupshaped or piston valve 32 which is normally forced to its inward position by a coil spring 33. As shown, the valve 32 has a projecting pin 34 which limits its inward movement. The coil spring 33 has its opposite end disposed within a 'through an opening.

screw threaded adjusting screw 35, the adjust- 'ment of which predetermines the tension on the spring 33 to regulate the pressure necessary to move the valve 32 to its open position. Thus it will be apparent-that when the pressure generated by the pump an is suflicient to overcome the tension of the-spring 33, the valve 32 is moved to the left. In the normal position of the valve 32, the lateral outlet passage 38 which is disposed at substantially right angles to the passage 3| and which communicates therewith through ports 36a, is uncovered. The passage 36 communlcates with a suitable fitting 36' on the outer side of the member I I to receive a suitable delivery tube for conveying liquid, for instance, to and from a cylinder (not shown) for operating a piston. The passage 33 leads to both sides the member Ill in order that two tubes may, if desired, be connected, one leading to one apparatus to be operated, and the other to another.

In the inward or normal position of the valve 32, it will be understood that the ports 33a are disposed in a rear of the valve and uncovered thereby,-so that liquidmay return from the passages 38 to the reservoir through passage 3|, port 33 and return tube 31. In this manner liquid may be drained out of the passages 36 and tubes which are connected to the same, when the pump is not operating. ,In such event the same passagesenable liquid to flow to and from the reservoir.

In the event the force of the liquid from the pump 20 exceeds the pressure required to uncover the outlet passage 36, the valve 32 is still further depressed sufliciently to uncover a circumferential groove or port-39 leading to the return tube 3! whichis similar to the tube 25 and is likewise carried by the member H. In this manner liquid can be by-passed back to the reservoir l2 whenever a predetermined pressure builds up to overcome the resistance of the coilspring 33, such pressure being in excess of that necessary to move the valve to uncover the passage 36.

Drilled through the member II on opposite v sides of thehousing for the valve 32, are ports 38 which are arranged within a chamber 38' formed in the upper side of the member H. A plate 40 closes the top of this chamber and the latter communicates with the atmosphere Thus the inside of the reservoir i2 is open to the outside, through the ports 38, chamber 38' and port ll. In this man-- ner the liability of a partial vacuum or pressurebeing created within the reservoir is eliminated.-

A groove 42' in the valve housing enables fluid in rear of the valve and in front of the adjusting plug 35 to be relieved in order that free valve movements may be secured.

Bracket 42 and bosses 43 enable the assembly to be readily mounted in position of use. Thus separate mounting for the motor, the pump and the reservoir are dispensed with and these parts are compactly arranged in a single unit which can be installed without difficulty.

It is to be understood that numerous changes in details of construction, arrangement and operation may be effected without departing from the spirit of the invention especially as defined in the appended claims.

What I claim is:

1. A pump unit having a pump for generating pressure fluid having an inlet and an outlet, a pressure fluid supply, means providing communication between said supply and the inlet of-said pump, a valve operating passage communicating at one end with the outlet of said pump and being closed at its opposite end, a piston valve reciprocable in said valve operating passage, a compression spring urging said valve toward a normal position adjacent the pump end of said valve operating passage, a port in said valve op-- erating passage disposed between the closed end thereof and the spring engaging end of the valve when the latter is in normal position, a main passage leading from said port for conducting fluid to or from said valve operating passage, a drain port in said valve operating passage disposed between the closed end thereof and-said flrst'port, and a, return passage leading from said drain port to said pressure fluid supply, said valve being movable against the force of said spring in response to fluid pressure generated by said pump to establish communication between said valve operating passage and said first port and main passage and being further movable in response to excessive pressure to uncover said drain port, fluid from said main passage passing through said valve operating passage to said drain port when the valve is in normal position.

2. A pump unit having a body portion, a fluid reservoir suspended from said body portion, a fluid pump carried by said body portion and provided with an inlet and an outlet for fluid, said body portion having two radially extending passages respectively in communication with said inlet and outlet, two tubes for fluid extending respectively from said radially extending passages toward and terminating adjacent the bottom of said reservoir, one tube constituting a fluid supply line from the reservoir to one of said passages and the other of said tubes constituting a return line to the reservoir from the other of said passages, said other passage having an outlet port, valve means controlling the flow oi fluid from said other passage to said port and to said return line, and means for normally holding said valve means in position to establish communication between said outlet port and said return line through said other passage, said valve means being operable to establish communication between said pump and outlet port in response to fluid under pressure from said pump.

JOHN B. PARSONS. 

